Drug Targets in Prostate Cancer: An Appetite for KLK2-Mediated Destruction.

Human kallikrein (KLK) 2 is a prostate cancer tissue-specific protein that is regulated by androgen receptor signaling. KLK2 was not previously recognized as a therapeutic target as it was shown to be a secreted serine protease with no evidence for localization to the cell surface. It has now been demonstrated that KLK2 is expressed on the cell surface and is targetable by various methodologies. See related article by Shen et al., p. 4543.